The aim of the study was to identify the plant communities occurring in meliorated river valleys of the Lublin region. The studies included 10 river valleys. In total, 750 floristic photographs qualified into 39 plant communities were taken by means of Braun–Blanquet’s method. The occurrence of 10 communities from Molinio-Arrhenatheretea and 6 from Phragmitetea class was found in most valleys. They formed 90.28% of taken phytosociological photographs. The following communities from Molinio-Arrhenatheretea class were most frequent: Arrhenatheretum elatioris, Poa pratensis-Festuca rubra, Alopecuretum pratensis and Caricetum gracilis from Phragmitetea. In total, 42 grass species were found in all studied communities. Among 39 plant communities, 39 grass species were noted in 6 them, which means 92.85% of all occurring grasses. The landscape traits of meliorated river valleys were not so good as those with original plants.